Root/drivers/input/sparse-keymap.c

1/*
2 * Generic support for sparse keymaps
3 *
4 * Copyright (c) 2009 Dmitry Torokhov
5 *
6 * Derived from wistron button driver:
7 * Copyright (C) 2005 Miloslav Trmac <mitr@volny.cz>
8 * Copyright (C) 2005 Bernhard Rosenkraenzer <bero@arklinux.org>
9 * Copyright (C) 2005 Dmitry Torokhov <dtor@mail.ru>
10 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License version 2 as published by
13 * the Free Software Foundation.
14 */
15
16#include <linux/input.h>
17#include <linux/input/sparse-keymap.h>
18#include <linux/module.h>
19#include <linux/slab.h>
20
21MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
22MODULE_DESCRIPTION("Generic support for sparse keymaps");
23MODULE_LICENSE("GPL v2");
24MODULE_VERSION("0.1");
25
26static unsigned int sparse_keymap_get_key_index(struct input_dev *dev,
27                        const struct key_entry *k)
28{
29    struct key_entry *key;
30    unsigned int idx = 0;
31
32    for (key = dev->keycode; key->type != KE_END; key++) {
33        if (key->type == KE_KEY) {
34            if (key == k)
35                break;
36            idx++;
37        }
38    }
39
40    return idx;
41}
42
43static struct key_entry *sparse_keymap_entry_by_index(struct input_dev *dev,
44                              unsigned int index)
45{
46    struct key_entry *key;
47    unsigned int key_cnt = 0;
48
49    for (key = dev->keycode; key->type != KE_END; key++)
50        if (key->type == KE_KEY)
51            if (key_cnt++ == index)
52                return key;
53
54    return NULL;
55}
56
57/**
58 * sparse_keymap_entry_from_scancode - perform sparse keymap lookup
59 * @dev: Input device using sparse keymap
60 * @code: Scan code
61 *
62 * This function is used to perform &struct key_entry lookup in an
63 * input device using sparse keymap.
64 */
65struct key_entry *sparse_keymap_entry_from_scancode(struct input_dev *dev,
66                            unsigned int code)
67{
68    struct key_entry *key;
69
70    for (key = dev->keycode; key->type != KE_END; key++)
71        if (code == key->code)
72            return key;
73
74    return NULL;
75}
76EXPORT_SYMBOL(sparse_keymap_entry_from_scancode);
77
78/**
79 * sparse_keymap_entry_from_keycode - perform sparse keymap lookup
80 * @dev: Input device using sparse keymap
81 * @keycode: Key code
82 *
83 * This function is used to perform &struct key_entry lookup in an
84 * input device using sparse keymap.
85 */
86struct key_entry *sparse_keymap_entry_from_keycode(struct input_dev *dev,
87                           unsigned int keycode)
88{
89    struct key_entry *key;
90
91    for (key = dev->keycode; key->type != KE_END; key++)
92        if (key->type == KE_KEY && keycode == key->keycode)
93            return key;
94
95    return NULL;
96}
97EXPORT_SYMBOL(sparse_keymap_entry_from_keycode);
98
99static struct key_entry *sparse_keymap_locate(struct input_dev *dev,
100                    const struct input_keymap_entry *ke)
101{
102    struct key_entry *key;
103    unsigned int scancode;
104
105    if (ke->flags & INPUT_KEYMAP_BY_INDEX)
106        key = sparse_keymap_entry_by_index(dev, ke->index);
107    else if (input_scancode_to_scalar(ke, &scancode) == 0)
108        key = sparse_keymap_entry_from_scancode(dev, scancode);
109    else
110        key = NULL;
111
112    return key;
113}
114
115static int sparse_keymap_getkeycode(struct input_dev *dev,
116                    struct input_keymap_entry *ke)
117{
118    const struct key_entry *key;
119
120    if (dev->keycode) {
121        key = sparse_keymap_locate(dev, ke);
122        if (key && key->type == KE_KEY) {
123            ke->keycode = key->keycode;
124            if (!(ke->flags & INPUT_KEYMAP_BY_INDEX))
125                ke->index =
126                    sparse_keymap_get_key_index(dev, key);
127            ke->len = sizeof(key->code);
128            memcpy(ke->scancode, &key->code, sizeof(key->code));
129            return 0;
130        }
131    }
132
133    return -EINVAL;
134}
135
136static int sparse_keymap_setkeycode(struct input_dev *dev,
137                    const struct input_keymap_entry *ke,
138                    unsigned int *old_keycode)
139{
140    struct key_entry *key;
141
142    if (dev->keycode) {
143        key = sparse_keymap_locate(dev, ke);
144        if (key && key->type == KE_KEY) {
145            *old_keycode = key->keycode;
146            key->keycode = ke->keycode;
147            set_bit(ke->keycode, dev->keybit);
148            if (!sparse_keymap_entry_from_keycode(dev, *old_keycode))
149                clear_bit(*old_keycode, dev->keybit);
150            return 0;
151        }
152    }
153
154    return -EINVAL;
155}
156
157/**
158 * sparse_keymap_setup - set up sparse keymap for an input device
159 * @dev: Input device
160 * @keymap: Keymap in form of array of &key_entry structures ending
161 * with %KE_END type entry
162 * @setup: Function that can be used to adjust keymap entries
163 * depending on device's deeds, may be %NULL
164 *
165 * The function calculates size and allocates copy of the original
166 * keymap after which sets up input device event bits appropriately.
167 * Before destroying input device allocated keymap should be freed
168 * with a call to sparse_keymap_free().
169 */
170int sparse_keymap_setup(struct input_dev *dev,
171            const struct key_entry *keymap,
172            int (*setup)(struct input_dev *, struct key_entry *))
173{
174    size_t map_size = 1; /* to account for the last KE_END entry */
175    const struct key_entry *e;
176    struct key_entry *map, *entry;
177    int i;
178    int error;
179
180    for (e = keymap; e->type != KE_END; e++)
181        map_size++;
182
183    map = kcalloc(map_size, sizeof(struct key_entry), GFP_KERNEL);
184    if (!map)
185        return -ENOMEM;
186
187    memcpy(map, keymap, map_size * sizeof(struct key_entry));
188
189    for (i = 0; i < map_size; i++) {
190        entry = &map[i];
191
192        if (setup) {
193            error = setup(dev, entry);
194            if (error)
195                goto err_out;
196        }
197
198        switch (entry->type) {
199        case KE_KEY:
200            __set_bit(EV_KEY, dev->evbit);
201            __set_bit(entry->keycode, dev->keybit);
202            break;
203
204        case KE_SW:
205        case KE_VSW:
206            __set_bit(EV_SW, dev->evbit);
207            __set_bit(entry->sw.code, dev->swbit);
208            break;
209        }
210    }
211
212    if (test_bit(EV_KEY, dev->evbit)) {
213        __set_bit(KEY_UNKNOWN, dev->keybit);
214        __set_bit(EV_MSC, dev->evbit);
215        __set_bit(MSC_SCAN, dev->mscbit);
216    }
217
218    dev->keycode = map;
219    dev->keycodemax = map_size;
220    dev->getkeycode = sparse_keymap_getkeycode;
221    dev->setkeycode = sparse_keymap_setkeycode;
222
223    return 0;
224
225 err_out:
226    kfree(map);
227    return error;
228}
229EXPORT_SYMBOL(sparse_keymap_setup);
230
231/**
232 * sparse_keymap_free - free memory allocated for sparse keymap
233 * @dev: Input device using sparse keymap
234 *
235 * This function is used to free memory allocated by sparse keymap
236 * in an input device that was set up by sparse_keymap_setup().
237 * NOTE: It is safe to cal this function while input device is
238 * still registered (however the drivers should care not to try to
239 * use freed keymap and thus have to shut off interrups/polling
240 * before freeing the keymap).
241 */
242void sparse_keymap_free(struct input_dev *dev)
243{
244    unsigned long flags;
245
246    /*
247     * Take event lock to prevent racing with input_get_keycode()
248     * and input_set_keycode() if we are called while input device
249     * is still registered.
250     */
251    spin_lock_irqsave(&dev->event_lock, flags);
252
253    kfree(dev->keycode);
254    dev->keycode = NULL;
255    dev->keycodemax = 0;
256
257    spin_unlock_irqrestore(&dev->event_lock, flags);
258}
259EXPORT_SYMBOL(sparse_keymap_free);
260
261/**
262 * sparse_keymap_report_entry - report event corresponding to given key entry
263 * @dev: Input device for which event should be reported
264 * @ke: key entry describing event
265 * @value: Value that should be reported (ignored by %KE_SW entries)
266 * @autorelease: Signals whether release event should be emitted for %KE_KEY
267 * entries right after reporting press event, ignored by all other
268 * entries
269 *
270 * This function is used to report input event described by given
271 * &struct key_entry.
272 */
273void sparse_keymap_report_entry(struct input_dev *dev, const struct key_entry *ke,
274                unsigned int value, bool autorelease)
275{
276    switch (ke->type) {
277    case KE_KEY:
278        input_event(dev, EV_MSC, MSC_SCAN, ke->code);
279        input_report_key(dev, ke->keycode, value);
280        input_sync(dev);
281        if (value && autorelease) {
282            input_report_key(dev, ke->keycode, 0);
283            input_sync(dev);
284        }
285        break;
286
287    case KE_SW:
288        value = ke->sw.value;
289        /* fall through */
290
291    case KE_VSW:
292        input_report_switch(dev, ke->sw.code, value);
293        break;
294    }
295}
296EXPORT_SYMBOL(sparse_keymap_report_entry);
297
298/**
299 * sparse_keymap_report_event - report event corresponding to given scancode
300 * @dev: Input device using sparse keymap
301 * @code: Scan code
302 * @value: Value that should be reported (ignored by %KE_SW entries)
303 * @autorelease: Signals whether release event should be emitted for %KE_KEY
304 * entries right after reporting press event, ignored by all other
305 * entries
306 *
307 * This function is used to perform lookup in an input device using sparse
308 * keymap and report corresponding event. Returns %true if lookup was
309 * successful and %false otherwise.
310 */
311bool sparse_keymap_report_event(struct input_dev *dev, unsigned int code,
312                unsigned int value, bool autorelease)
313{
314    const struct key_entry *ke =
315        sparse_keymap_entry_from_scancode(dev, code);
316    struct key_entry unknown_ke;
317
318    if (ke) {
319        sparse_keymap_report_entry(dev, ke, value, autorelease);
320        return true;
321    }
322
323    /* Report an unknown key event as a debugging aid */
324    unknown_ke.type = KE_KEY;
325    unknown_ke.code = code;
326    unknown_ke.keycode = KEY_UNKNOWN;
327    sparse_keymap_report_entry(dev, &unknown_ke, value, true);
328
329    return false;
330}
331EXPORT_SYMBOL(sparse_keymap_report_event);
332
333

Archive Download this file



interactive